Block-signal



(No Modem L: C. SMITH. 4 sheets-sheen* BLOGK SIGNAL. Y No. 569,246.yPamted 001;'. 1s, 1896..'

(No Model.) 4' Sheets-Sheet 2.

L. C. SMITH.

BLOCK SIGNAL. l N6. 669,246. Patented 066. 16', 1696.

2 @A ll Zell/lfm. 124// Ky@ v V 7,- a *@/qbT/Leowo agg/1166660@ N Ko ma6 4% 6 6 i attenua/t? mi Nonna: News cu, Pam-aufm.. wnsuwmsu. u. c.

4 Sheets-Sheet `3 L. G. SMITH. BLOGK SIGNAL.

(No Model.)

No. 569,246. Patented Oct. 13, 1896.-

.N ww .m4 Sww@ .MN wh .,ix ,.I.. 15:1... 0 t M. a 5: oli.; u FT 1 uf???...\4.. T|.w 1......

(No Model.) Y 4 sheets-sheet 4.

L. C. SMITH. BLOCK SIGNAL.

No. 569,246. Patented Oct. 13, 1896.

NrTnD STATES PATENT rrrcn.

LUTHER C. SMITH, OF CARBONDALE, PENNSYLVANIA.

BLOCK-SIGNAL.

'SPECIFICATION forming' part 0f Letters Patent No. 569,246, dated.October 13, 1896.

Application filed July 9, 1895. Serial No. 555,426. (No model.)

To all wiz/0771, t muy concern:

3e it known that I, LUTHER C. SMITH, a citizen of the United States,residing' at Carbondale, in the county of Lackawanna and State ofPennsylvania, have invented certain new and useful Improvements inBlock-Signals, of which the following is a specification.

My invention relates to automat-ic blocksignals for railways.

The object of the invention is to provide a semaphore or other signalwhich shall be set to danger automatically as a train enters the blockand looked in such position until it is automatically unlocked byelectric or other connections between the signal and points at the otherend of said block or on the succeeding block as the train reaches suchpoints. I provide a set or' locking devices which all lock at once asthe signal is set to danger and which may be arranged to unlockindividually by three successive impulses sent back over one or morewires as the train proceeds, or by twoimpulses, or on e, as desired."Where three impulses are given to unlock the signal, I may, forinstance, arrange a track instrument at the succeeding station onethousand feet beyond the station to indicate when the train, if ofordinary length, has lett the block and one a little farther on toinsure safety, or I may use push-buttons at such points and operate themby hand. In addition to unlocking the signal the impulses sent over thewire as the train passes the track instruments or points where thepushbuttons are located serve to notify the operator at the initial endof the block when the train arrives at the opposite end of the block andalso when it leaves the block, the track instruments being so spacedthat the last one will not be operated until the train has entirely leftthe block.

The object in using a series of locking devices and unlocking themsuccessively is to insure absolute safety in the use of an automaticsignal. It often happens that a track instrument or other circuit-closerwill be operated accidentally, and if a single track instrument weredepended upon in the present instance the signal might be accidentallydropped to the safety position at improper times. By using a series oflocking devices the si guai cannotbe dropped by the accidental closingof any one of the track instruments or by the closing of all them inreverse order. It can only be dropped by closing the track instrumentssuccessively and in proper order. Accidental closing of theinstrumentsin this manner is almost impossible.

I shall now proceed to describe the signal operating and lockingmechanism for each block-station and afterward the several arrangementsof circuits by which the signal may be operated, reference being had tothe accompanying drawings, in which- Figure l is a section through therails of a track, showing in elevation'and partly in section asemaphore-signal and its operating mechanism. Fig. 2 is an elevation ofthe signal and operating mechanism, looking upon the left side in Fig.l. Figs. 3, at, and 5 show three difterent positions of the unlockingdevices. Fig. 6 is a side view of the spring-rail, which is used to setthe signal to dangen Fig. 7 is a diagram showing the electricalconnections. Fig. 8 is a side view of one of the interlockingsafety-catches. Fig. 9 is an end view of the catches, showing theinterlocking portions; and Fig. lO is a diagram showing an applicationof the invention.

Referring to Figs. l to 5, inclusive, l represents an ordinarysemaphore-signal mounted on a post 2 and operated by a rod 3, the signalbeing set to danger7 when the rod is pulled down, and vice versa. Therod 3 is connected by a turnbuckle 4 and link 5 with a semiannulargravity-lever 6. Then the signalis at danger or horizontal, the lever 6is raised and locked in that position by an armature-lever 7, whichengages a notch 8 in the upper end of t-he lever 6, and also by anarmature-lever 9, which hooks over a projection or detent l0 on lever 6,as shown in Figs. l to 5, inclusive.

To the lower end of the signal-rod 3 is connected a weight IV bymeans ofchains or other connections ll, said chains being also connected to alever 12, pivoted, as shown in the drawings, to a cross-timber l3,whichmay eX- tend under the rails 14 and form one of the cross-ties of therailway. To the end of the lever l2 the lower end of a secondgravity-lever l5 is connected by alink 16. This gravitylever l5 has anotch l in its upper end, which IOO is also engaged by thearmature-lever 7, and it carries a projection or detent 18, whichengages an elongated notch in an armature-lever 19, similar to the lever9, but extending in the opposite direction.

The weight IV rests upon an operating-lever 20, which is pivoted to asuitable support. As shown, it is pivoted to a hanger 21, supported fromone of the rails 14. Upon an arm of the lever which extends under thetrack is a weight IV', which preponderates over the weight W and keepsit normally raised, as shown in Figs. 3 to 5, inclusive. lVhen atrainpasses the station, the wheel-flanges depress a spring-rail 22, which inturn depresses a connection or arm 23 of the lever 2O and throws downthe inner end of said lever, thus lowering the weight IV and raising theweight W. The weight IV as it is lowered draws down the lever 12 and theconnecting-chains 1l, which, in turn, throws up the danger-signal andthe locking-arms G and 15, said arms being immediately engaged by thearmature-levers and locked.

It is desirable that the lever 20 should be operated but once by eachtrain, and that it should not be subjected to separate jar or vibrationfor each wheel in the train. For Vthis reason I prefer to use a dash-potor other equivalent means to hold the inner end of the lever down whenit is depressed, and I preferably arrange to keep the lever down untilthe train has passed to the other end of the block. As shown, the innerend of the lever is connected by a rod 24 with a piston 25 in anaircylinder 26. lVhen the lever is depressed, the piston is drawn downand air is permitted to enter freely above the piston through aspringvalve 27 ,which, however, does not permit any air to escape. Asmall pipe 2S, communicating with the upper end of the cylinder, isprovided with a rotary valve 29, operated by a lever 30, which ispivotally connected with the armature-lever 7 by means of a crank-pin31. Vhen the piston 25 is depressed, the valve 29 is closed and it isnot opened again until the train reaches the opposite end of the block,as will be hereinafter explained, and during the time the train occupiesthe block the inner end of the lever 20 is depressed, as shown inFig. 1. The armature-levers 7, 19, and 9 are operated, respectively, byelectromagnets A, B, and C, the levers being provided with suitablearmatures.

When my improved signal is used with a single wire for unlocking theseveral locking devices, I provide the locking-arms G and 15 with a pairof safety-catches 33 to prevent the locking-arms from droppingsimultaneously, or nearly so, should the current be kept on long enoughto unlock both arms by the same impulse. In such case the safety-catcheswould interfere and prevent the arms from dropping, and thus hold thesignal at danger until the catches are released, which may be done byagain raising the signal and locking-arms by hand or by the spring-railor track instrument. As shown particularlyin Figs. 2, S, and 9,thesecatches consist of springarms 34, mounted upon shafts 32, to which thelocking-arms are rigidly connected. These arms cross each other, asshown in Fig. 1, when the locking-arms are raised. Near the outer end ofthe arms are interlocking projections 33, so beveled that when thelockingarms are raised these projections or safetycatches easily passeach other, the springarms yielding sufficiently to permit the in-Vclined surfaces to slide one upon the other. The rear sides of theprojections 33 are square, and should the locking-arms tend to dropsimultaneously the projections 33 would engage each other and preventthe arms from dropping and the signal from being lowered. Then only oneof the locking-arms is dropped, however, the projection 33 upon onesafetycatch will pass over the projection on the other and there will beno interference between them.

The operation of setting the signal at danger as a train enters a blockis as follows: The irst wheel of the train depresses the springfrail 22and lowers the inner end of the lever 20, which is held depressed untilthe train passes by the piston 25 in the air-cylinder. Before thearrival of the train the parts were in the position shown in Fig. 5, thelocking-arms 6 and 15 being down and the signal dropped to safety W'henthe inner end of the lever 2O is forced down, the weight W drops andpulls down the operating-rod 3, thus throwing the blade of the signal 1up to the horizontal or danger7 position. It will be noted that thedepression of the springrail 22 does not directly operate the lever. Itsimply removes the support from under the weight IV and allows theweight to fall. By means of this arrangement a very sudden movement ofthe lever 2O can do no harm to the signal and its operating mechanism,as it need not be accomplished by a corresponding sudden movement of theweight W. The weight W in descending also throws the locking-arm 6 upinto engagement with the armature-levers 7 and 9 and simultaneouslythrows the rocking lever 15 into engagement with the armature-levers 7and 19. The parts then remain in the position shown in Fig. 1 until thearmature-lever 7 is operated as the train passes the succeeding station,as will bew explained presently. Y

In Fig. 7 I have shown an arrangement of circuits by means of which themagnets A, B, and C at each station are operated successively to unlockthe signal from its danger position, thus forming a sort ofcombination-lock which insures great security in the use of myblock-signals.

I shall iirst describe the circuits as they are shown diagrammaticallyin Fig. 7 and afterward show one way in which they may be practicallyapplied to the signals shown in the other f1 gures. Fig. 7 shows threestations marked, respectively, R, S, and T. As a train TOO IIO

IIS

passes the station T, say toward station S, it sets the signal atT todanger, as above described. A line-wire s extends from station T tostation S, and the circuit through this wire is completed by a trackinstrument s at station S as the train arrives at that station. Thecurrent sent through the line-wire passes through a switch fr, throughmagnet A and to ground through wire G. The switch c: is connected to thearmature of the magnet A and the operation of the armature throws theswitch over, connecting the line s with a branch to switch y, the switchc being held in this position by suitable means, as will be explainedlater. The second track instrument s2 is designed to show when the trainhas entirely passed the station S and left the precedin gblock,an dhence this instrument should be one thousand feet or more beyond stationS. lVhen the track instrument s2 is operated, the current passes throughswitches a; and y and magnet B to ground, operating the armature of themagnet B and simultaneously throwing the switch y into the dottedposition to convey the next impulse over the line through magnet C.YVhen the line is completed through track instrument s3, the currentwill pass through switches @aand y and magnet C to ground, thusoperating the magnet C. The operations above outlined will be repeatedt'or each block.

I shall now describe the operation of the circuits as applied toreleasing the signal, referring to Figs. 1 to 5,inclusive. Assuming thatthe train has just passed the signal and entered the block, the lockingdevices will be in the position as shown in Fig. 1. W'hen the trainreaches the other end of the block, the .first track instrumentcompletes the circuit through magnet A and draws down the armature onlever 7, raising the opposite end of the lever. This releases thelocking-arms 6 and 15 and they drop backward until the proj ections 10and 18 are caught in the hooks of the levers 9 and 19, as shown in Fig.3. The hooks at the ends of the locking-levers remain under and supportthe end of the armature-lever '7, holding it up until both lockinga-rmsare dropped. The movement of the armature-lever 7, above described,opens the valve 20 and releases the air from the cylinder 2G, permittingthe weight IV/ to fall and raise the lesser weight IV. The tongue of theswitch a; is connected in some suitable manner with the lever 7, so thatas the lever is moved the switch is thrown, thus connecting the circuitthrough the branch to the switch y. As shown in Fig. 2, the switch isconnected to the pivot of the armaturelever. The next current-impulseover the line-wire passes through the magnet B and operates the lever19, thus unhooking the locking-arm and permitting it to drop, as shownin Fig. l.

It maybe here stated that the arm 15 must always drop before the arm 6because the stift link 1G holds the lever 12 down as long as the arm 15is up, and the lever l2, through the chain 1l and link 5, holds the arm6 up as long as the lever 12 is held down. It is thus necessary that thearm 15 should drop before the arm 6 can be dropped. The switch y isoperated simultaneously with the magnet B in some suitable manner. Asshown in Fig. 1, it is connected with the pivot of the lever 15, saidpivot turning with the lever. The current-impulse sent over theline-wire by the third and last track instrument passes through themagnet C, which operates the lever 9 and releases the locking-arm 6. Thearm G immediately drops to the position shown in Fig. 5, thus forcing upthe rod 3 and lowering the signal 1. The signal then indicates that theblock is clear and the next coming train may pass in, and entering theblock it will set the signal to danger, as above described.

The track instruments may be of any approved construction, or one ormore of them may be simply track-circuits which are normally broken andwhich will be completed by the wheels and axles of the trains when theypass. If ordinary track instruments are used, they should be providedwith dash-pots or some means to prevent the instrument from beingoperated more than once by the same train.

I contemplate using my improved signal and the locking and unlockingdevices, in some instances, by substituting ordinary push-buttons forthe track instruments, the push-buttons being located at block-signaltowers, or other suitable points, and operated by hand. Thecurrent-impulses which operate the unlocking devices may also be made tooperate bells or an annunciator to indicate the location of the trainwhich has passed.

I have described above the arrangement of circuits for unlocking thesignals by three separate impulses over the same line-wire. It will beevident that I -may dispense with the switches and y and use threeline-wires, one from each track instrument to its appropriate magnet. Imay also use a circuit-wire, as shown, and dispense with the switch y,sending the current first through the magnet A and then simultaneouslythrough the magnets B and C, and in some instances I may furthersimplify the arrangement and send the current through all three of theoperatingmagnets at once, in which `case the safetycatches must beremoved. These several modifications depend upon simple and obviouschanges in the arrangement of the switches and circuits. Some othersuitable retarding device may be substituted for the cylinder 26, itbeing only essential to hold the lever down until the train has passedover the rail 22.

In Fig. 7 I have shown in broken lines circuits U, connecting alternatestations along the line. In some instances I prefer to use thisarrangement instead of connecting each station with the preceding one.By connect- IOO IIO

ing alternate stations there will always be two signals set at danger inthe rear of each train.

In Fig. lO I have shown my improved signal as used in connection withordinary blocksignal towers. By placing one of my automatic signals inthe middle of each block and providing circuits by means of which theoperators at the ordinary signal-towers at the ends of the block mayunlock the automatic signal I have been able to double the traincapacity of the block-signal now commonly used. In this figure, N and Pindicate blocksignal towers of the ordinary kind, in which operators areemployed to set the signals for passing trains. Between the stations Nand P, at O, is erected one-of my automatic signals, which isrepresented diagrammatically by the magnets A, B, and C, correspondingto similar magnets on the other figures of the drawings. In this casethe magnets are energized and the unlocking devices operated overseparate wires, the magnets A and B being connected with the tower P bywires a and b, respectively, and the magnet C being connected to thetower N by wire c. The wires a and b are provided with circuit-closers aand b', located in the tower P, and the wire c is provided with asimilar device in the tower N. As shown, the magnets A, B, and C areenergized from a common battery D at the station O, one terminal ofwhich is connected to the rails or ground and the circuits through thewires ce, b, and c are completed through the ground-wires II and II atstations P and N. `In addition to these circuits there is a wire Lbetween the towers P N, which wire is grounded at each tower through theground-wires II and H common to the other circuits. At each tower asingle bell or annunciator F is in circuit with the wire L. The wire Lis connected at the station O by a wire Z to the track instrument othrough the battery E. It will therefore be seen that when the trackinstrument 'is operated by the passage of a train the current will passthrough Z, divide at L, operate the si gnal-bells F F, return through HH and the ground or rails to the battery. G is the ordinary telegraphtrain-wire. The operation is as follows: IVe will assume that all thesignals indicate a clear track and that a train is approaching station Nand proceeding toward station O. After passing station N the operator atthat tower will set his signal at danger. As the train passes thestation O it automatically sets the signal at danger in the mannerheretofore described and operates the track instrument o', sending anelectrical impulse through Z, which divides at L, passes through theannunciators F, thereby notifying the operators at N and P that it haspassed station O. The operator at N is then free to lower his signal andadmit another train to the first half of the block between IT and P,thus permitting two trains to occupy said block. lVhen train No. larrives at station P, the operator closes circuit a and after it passesthis station he closes circuit b, thus operating the magnets A B andopening their locking devices. At the same time the operator at Pnotifies the operator at N over the train-wire Gr that the train haspassed P, and the operator at N, through circuit c, operates the lastlocking device and drops the signal at O to indicate that the subblockbetween O and P is clear. In this manner the train capacity of theordinary block-signal system may be doubled without increasing `thenumber of operators and without any danger of misunderstanding oraccident.

It will be evident that my invention is capable of various modificationsin construction and arrangement other than those above pointed out.claims to the precise form shown and described, but

lVhat I claim is- 1. In a block-signal system, a signal and means forsetting the same to danger, a series of locking devices operatedsimultaneously to lock said signal in the danger position upon thepassage of a train, and means for unlocking said devices successively,substantially as described.

2. In a block-signal system, a signal and a series of locking devicesadapted to lock said signal in the danger position, means for settingthe signal to danger and automatically locking it with said devices, andmeans for automatically unlocking said devices successively,substantially as described.

3. In a blockv signal system, the combination of a signal, and means forsetting the same to danger,a series of locking devices for locking thesignal in the danger position, a series of magnets for unlocking saiddevices, and means for energizing said magnets successively,substantially as described.

4. In a block-signal system, a signal and means for setting the same todanger, a series of locking devices for said signal, and mechanism forunlocking said devices successively, including an elec-tromagnet foreach device, a circuit or circuits for said magnets, and means forclosing the circuit or circuits and exciting the magnets successively,substantially as described.

5. In a block-signal system, a signal and mechanism for automaticallysetting the signal to danger upon the passage of a train, a series oflocking devices for locking said signal in the danger position, acorresponding series of magnets, adapted, when energized, to unlock saiddevices, a series of track instruments, and electrical connectionsbetween the track instruments and the magnets, whereby the successiveoperation of the track instruments will operate the magnets and unlockthe locking devices successively, substantially as described.`

6. In a block-signal system, a signal arranged to normally assume thesafety position, a weight attached to said signal by a I do nottherefore limit my IOO IIC

chain or flexible connection and adapted to throw it to danger, a leverupon one end of which said weight is supported, a counterweight uponsaid lever for normally supporting the weight and permitting the signalto stand in the safety position, and a track instrument operating on thesupport for the weight and arranged to lower said support and raise thecounterweight upon the passage of a train, thereby permitting the weightto set the signal to dangerj substantially as described.

7. In a railway block-signal, the combination of the signal proper, aweight attached to and arranged to hold the signal in the dangerposition, a locking device constructed to lock the signal in the dangerposition, said locking device being connected to and operated by saidweight, a support independent of the locking device and arranged to holdsaid weight in an elevated position, and means for lowering said supportupon the passage of a train, thereby permitting the weight to set thesignal to danger and lock the saine, substantially as described.

S. In a railway-signal, the combination with the signal proper and thesign al-operatin g rod, of a pair of locking-arms connected with therod, a common armature-lever for locking both of said arms, a pair ofindependent armature-levers for locking the arms separately, and meansfor operating said levers to unlock the arms, substantially asdescribed.

D. In a railway block-signal, the combination of the signal proper, thesignal-operating rod, the locking-arms, the weight connected to thesignal and locking-arms and arranged to raise the same, and means forreleasing said locking-arms, said signal and lockingarms being arrangedto drop by gravity when released, substantially as described.

l0. In a railway block-signal, the combination with the signal proper,of the lockingarms and means for releasing said arms successively, andthe safety-catches connected with said locking-arms and arranged toprevent said arms from dropping simultaneously, substantially asdescribed.

l1. In a railway block-signal, the combination with the signal proper,and the operating-rod having its upper end connected With the signal, ofthe weight connected with the lower part of said rod for setting thesignal to danger, a support for normally holding the weight in its upperposition, means for lowering said support upon the passage of a train,thereby permitting the weight to set the signal to danger, and adash-pot or equivalent device for holding said support temporarily inits lower position,substantially as described.

l2. In a railway block-signal, the combination with the signal proper,the signal-operating rod, and the weight connected to said rod by achain or equivalent flexible connection, of a lever supporting saidweight, a counterweight upon the lever sufficient to hold the Weightnormally in an elevated position, means for raising the counterweightupon the passage of a train, and means for holding said counterweighttemporarily in an elevated position, substantially as described.

13. In a railway block-signal, the combination with the signal properand the signal-operating rod, of the weight W, the lever upon which thesaid weight rests, the counterweight upon the opposite end of the lever,the spring-rail arranged to operate said lever upon the passage of atrain, the air-cylinder and piston arranged to hold the counterweightelevated, and means for releasing the air, substantially as described.

In testimony whereof I afx my signature in presence of two witnesses.

LUTHER C. SMITH. Vitnesses:

G. W. KEENE, W. R. BAKER.

